In the wire fabricating industry, it is common practice to weld a trailing end section of a first wire to a leading end section of a second wire in order to maintain a continuous supply of wire for the continuous operation of wire processing equipment.
This welding operation, which may be either hot or cold, is accompanied by the application of forces along the axes of the respective wires so that the abutted wire ends are upset to form a bulge and/or flash at the welded joint. The formation of this bulge would interfere with the subsequent processing of the wire, and numerous diverse types of apparatus have been developed to remove the weldment bulges and flash.
In one class of welding apparatus, the wire sections are gripped by pairs of welding electrodes. The pairs of electrodes are electrically heated and forcibly moved toward each other to abut the trailing end of one wire against the leading end of a second wire, resulting in a bulging out of the wire material about the welded joint. These welding electrodes are formed with projecting conical heads that are forced toward each other during the welding operation to shear the bulging wire material at the joint. An example of this type of apparatus is shown in U.S. Pat. No. 2,945,117 issued to J. F. Harris et al. on July 12, 1960. As described in the Harris et al. patent, a substantial portion of the weldment bulge is removed but there still remains a pair of projecting weldment fins which are subsequently removed by moving the wire and the fins against a pair of stationary cutters.
Another type of apparatus is exemplified by a patent to R. L. Filkorn, U.S. Pat. No. 3,790,098, issued Feb. 5, 1974, where the ends of two workpieces are forced together and spun to effectuate a fusing of the workpieces. This fusing operation also results in the formation of a weldment bulge which is substantially removed by the movement of a pair of semi-conical dies along the joined workpieces to abut and cut the weldment bulge.
Another class of apparatus contemplates a coldwelding operation where the end sections of a pair of wires are again gripped between two pairs of jaws having projecting conical cutters. The pairs of jaws are moved toward each other to abut the ends of the wires with sufficient force to fuse weld the ends of the wires. This fusing action is accompanied by a bulging of the upset ends of the wires. The jaws are further moved together so that the conical cutters move toward each other to shear the bulge. An example of this type of apparatus is disclosed in U.S. Pat. No. 2,920,511 issued Jan. 12, 1960, to K. F. Johnson.
U.S. Pat. No. 3,227,851 issued to U. I. Greenberger on Jan. 4, 1966, shows welding apparatus for heat welding the ends of two flat strips. The respective strips are clamped, heated and then forced together so that there is a bulging of the material at the welded joint. The weld bulge or flash is removed by moving two sets of cutting dies transversely of the strips. The sets of cutting dies are mounted to be progressively closer together so that the cutting dies progressively shave the weld flash.
These prior art devices are generally satisfactory for removing weld bulges where the welded stock is of a relatively large size. However, these devices are not suitable for removing weld bulges from wires of relatively small diameter, for example, 26-gauge wire. In these situations, the usual practice has been to remove the weld bulge by moving or rubbing an emery cloth over the weldment bulge. Inasmuch as the wires are joined by a coldwelding operation, there is a cold working of the metal, such as to lead to an embrittlement of the weldment. When the emery cloth is rubbed over the bulge, there is not only a wearing away of the bulge, but also an abrading of the relatively soft wire material on both sides of the weldment. It has been found that during the subsequent processing of joined wire sections through insulation applying equipment or cabling apparatus, a significant number of breaks occur in the wires at the weaker sites on either side of the removed weldment bulge.
In the manufacture of one type of cable known as pulp cable, small diameter wires of copper or aluminum are passed through a latex applicator and then through wiping dies which are slightly larger than the diameter of the wires. Each die exerts forces on the wire at the sections before and after the weldment. The forces often cause a break in the wire necessitating a re-welding operation and a re-stringing of the wire to pass through the wiping die.